Sheet feeding apparatus



Aug- 12, 1958 R. H. DUNcANsoN ET Al. 2,847,213

SHEET FEEDING APPARATUS 3 Sheets-Sheet 1 Filed Aug. 31, 1955 Aug 12, 1958 R. H. DuNcANsoN l-:T'AL 2,847,213

SHEET FEEDING APPARATUS s sheets-sheet 2 Filed Aug. 3l, 1955 wnw@ n n m ERO VCH mwc- DS H u To@ .ma am. ma. D M B RTTOR NE V Aug. 12, 195s R. H. DUNCANSQN mL 2,847,213

SHEET FEEDING APPARATUS INVENT0R5l BoBEET H. Duiven/usan 00A/QLD Ld. 56h/GEN 3 Sheets-Sheet 3 ATTozMsY Filed Aug. 5l, 1955 United States Patent O 2,847,213' srmErrEnniNGAPPARATUs RobertxH.. DuncansonglVIinneapn'lig. and `Donald' W. gSclloenp St.-- Paul,,Minn., assignoi's to General Mills,

Inc., a corporation of Delaware ApplicrihnAugust 31, 195s, srillNo. 531,788 anonime (oran- 62) 'flic present' application relates to1sheet I,feeding ap.- paratus and'more particularly, to improved apparatus for feedin'g'a'supply of'shets onboardsto atransfer station from which thesheets 'areto be removdfor further processing..

Various devices have been proposed in the pastfor the supply and feeding of a plurality of -she'etsto a transferV stationfrorn which the' individual sheets are tol be removedfora desiredoperation. `Some of thseprior'devicesnpresent problems and disadvantages in operation. Such problems may involve'the matterof replenishment of'the` supply ofsheets orboards and the .problems of limitation of the apparatusto asingle siie off'sheet'orA the.'` individual *sheets are fed byl Contact of. an. edge.

off; each: sheet with. `a movin'gbelt. l

A further objectis the provision'ofimproved"follower Inechanism for movement'. of such sheets. with a.. feeding belt:

`Still.` anotherfobject is an improved., follower. arrange.-

rnent :providing simple andv efficient replenishment of the.

sheetsupply Without interruption of thefeedingQoper'ation.

Another object is` the provisi'onof.` an improved. driving, mechanism and improved controls for. slchf a. sheet.

feedingeapparatus.

further object is the provision of improved driving.l

mechanism. operable in combination. with-anassociated conveyor rnerriber` which.- Visf'd'esi'gned". to.` handle the. sheets.

as they leavethe sheet supply transfer station.

-Stills another object is a sheet feevc'lirig4 apparatus .in .which provision isv made forconvenient adjustabihty to accom.- modate a` plurality of different sheet sizes.

Other-objects and.V advantages will be apparent from .the following specification in which certain preferred em: bodiments' of'etlie invention are describedwith particular reference to the accompanying drawings. In these drawings', in which like reference charactersindicate likeparts,

Figure l is a side view ofthe device according 'toA the present invention, with certain'portionsfbroken away and certain portionsshown in section for clearness;

jFi'g: 2Lis a'top viewfoft'he'device ofl'Figure l'with the'supply ofV sheets 'and certain otherelernentsremoved and with, some of'the` parts placed Vin Vdifferent. adjusted positions for conveniencevof description and illustration;

Figi 3iis a partial side viewshowingdetails'oftheadjustable 'mounting fory the upper guidemember;

Fig. 5 is-a sectionalview on thelines 5-5 of. Fig. 2; andl l Fig, 6'is a partial view takenfrom. the line1 6-6 of Fig. Z'showingdetails of the driving mechanism of. the feeding deviee.

ICC

General description As illustratedin Figs. 1 andv2, the\devicexof thepres-` ent inventionis designed. to moveafsupply of sheets on boards indicatedgenerally-atz10 to `a predeterminedftrans-` fer station at whichthe boards are to'be operatedfon'by another member. In this case,'the;individual boards; or.v sheets inthe supply 10-are1movedxtoward thetransferv station by engagementofone edge. ofl each boardwitha' moving belt 12. In the embodiment shown in the drawings, the belt `121includes. a horizontal portion on which the bottom edges of. thesheetmembers. rest. fln

.appropriate cases, the orientation. ofthe vbelt portions 12 can be modified to meet'particular operatingfconditions.

A guide member 14 isspaced from the beltas described below to position the sheetsat. the desired angle-as they,V approach the transfer station. One. orvmore inclined; ramps, such as that shown at- 16, engagel-the-leadngsheet tohold itat the transfer-station.

Thetransfer station is indicated in Fig. 1 by the position of the-leadingsheet 18. vFrom this transfer station, the leading sheet is to` be-removed by suitableapparatus which-forms no part'ofthepresent invention. Onefform.: of apparatus for this purpose is described in detail-below.

The. invention provides special. follower means for maintaining the sheets in position on'belt 12 and for assisting beltI 12 inl urging the-sheets toward the transfer. station. Thefollower meansincludes one or more.Y follower' members and preferably a combination of two,` such members, particularly designed to provide a simple. and convenienty method of replenishing the supply when. necessary. Special driving and.v control meansiare provided to move the belts and a follower member. towardlk thetransfer station,so that a new sheet willbe-presented. at the transfer station whenever the. previoussheet is re.- rnoved from that point. Details of the various-;parts,gin` cluding the driving mechanism, the reloading mechanism and the controlv features are set forth in greater detail below,together with a description of the-means byi'which the apparatuscanbe adjustedto' accommodate a plurality of different sizes offsheets.

Transfer mechanism.

As an'illus'tration of '-one type= of transfer ory operatingV apparatusfwith which the present sheet supply mechanism is particularly useful, Figure' 1i discloses atransfer meehanism by Whichslieets are removed'oneat a time from the-transferestation and deposited on the uppersurfa'ce of a-'horizon'talconveyor member. For this purpose, the transfer mechanism illustrated includes suction members 20A and 22 adaptedl to engage the leadingsheet` and to gripV said sheetby application of a suitable vacuum within the cups. The. suction cups are carried by va transfer member 24 supported by two-pivoted links 26 and 28. Certain features of this particular transfer mechanism are described and claimed in a co-pending application of Robert H. Duncanson, Serial No. 531,804 Vfiled vofl evendatetherewith. vAs described inrn'oreV detail in that application, the links 26 and 28 are located andl operatedr insuch al manner'as to move the leading sheet`18` from its initial transfer station to a horizontalposition on the-*topl of the conveyor belt portion 30. p

The-conveyor belt portion 30 isl supported by a suitable conveyor wheel 31- driven with a rotary shaft 32. In thev present case the shaft`32 rotates intermittently. It movesv the belt.30a suicient distance at each intermittent" ro-A tation to. advance one sheet or board away from theztransfer mechanism and thus provide space for' deposit of the, next sheet. The link Z6 of the transfermechanism is. reciprocated.- by a connectingrod 34 driven in the. manner. described in vthe above. co-pending. applicationjin timedA 3 sequence with the movement of conveyor shaft 32 and conveyor belt 30.

Other appropriate transfer devices or other operating mechanisms could be used in lieu of this specific transfer mechanism in appropriate cases for desired `operations on sheets presented successively at the transfer station 18. The mechanism of the co-pending application as illustrated in Figure 1 does provide a smooth and eicient combination, however, which, together with the present sheet supply apparatus, facilitates the movement of individual sheets to a processing station such as that represented by the horizontal portion of conveyor belt 30.

Sheet feeding mechanism As set forth most clearly in Figs. l and 2, the individual sheets are fed toward the transfer station by engagement of their lower edges with one or more movable belts, such as the belt 12. In the present apparatus, three such belts are provided as shown in Fig. 2. The belts are designated as 12, 36 and 38, respectively. Belt 12 is supported and driven by a suitable pulley or sheave 40, while belts' 36 and 38 are similarly carried and driven by sheaves 42 and v44, respectively. All of these pulleys or sheaves are suitably keyed to and driven by a rotary shaft 46, which is rotated by mechanism described below to advance the belts and move sheets to the transfer station as needed.

The rearwardly disposed ends of each of the belt portions 12, 36 and 38 are supported by similar pulleys 48, 50 and 52 carried `on a shaft 54 `supported for free rotation in bearings 56 and 58. Suitable guides are provided for the edges of the sheets to maintain them in the desired lateral alignment as they are fed toward the transfer station. For example, one edge of the apparatus is provided with stationary guide members 60 and 62 carried on vertical supporting brackets 64 attached to the main frame. An adjustable guide 66 is provided for the opposite edge of the sheets' and the method of support and adjustment for this guide member 66 is described in detail below.

F ollower mechanism According to an important feature of the present invention, an improved follower mechanism is provided to assist 'the belts in moving the sheets to the transfer station. The follower mechanism `is particularly designed and adapted to maintain the sheets at the desired angle for presentation to the transfer station. The follower arrangement is also adapted to simplify the reloading operation as additional sheets are needed.

To accomplish these objectives the invention contemplates the combination use of two improved follower units. One of these units is indicated at 68 in the form of a cross bar adapted for engagement with the two outside belts 12 and 36. The cross bar or body portion 68 of the follower carries an upwardly extending pusher member 70 and a horizontal base portion 71 attached at 72 to the body member 68. The pusher portion '70 is disposed at a predetermined angle designed to hold the rearwardly located sheets or boards at exactly the angle desired for the leading sheet at the transfer station.

To hold the follower member 68 in position during its movement toward or away Afrom the transfer station a suitable track 74 is attached by bolts 76 to the base plate 78 of this portion of the machine. reference to Figs. 2 and 4, the follower 68 includes a longitudinally extending guide or slide portion 80 adapted to engage the track 74 and insure movement of the follower 68 in a direction parallel to the belts. At the same time, this arrangement of the parts insures maintenance of the follower 68 in its position extending perpendicularly across the direction of feeding movement of the belts. This guide portion 80 includes flanges 82 adapted to engage beneath the edges of the track member 74. The guide member is' attached to the cross mem- With particular vll ber 68 by bolts 84 and is received in an appropriate cross-notch or channel in member 68 to maintain the parts in the desired relative orientation. Guide and track 74 hold the follower portion 70 at the desired upright angular position, where the belts alone might not have sutiicient rigidity to prevent tipping of the portion 70 out of such position.

In order to drive the follower member 68 with the belts, improved mechanism is provided to clamp the follower member in driving engagement with the belts and to release such clamping engagement during re-loading of the apparatus.

For this purpose, the follower member 68 includes a fixed clamping member 86 attached by bolt 88 at one edge of the follower. This fixed clamp 86 is located immediately adjacent the outer edge of belt 12 and includes an angular face adapted to tit one angular lateral face of belt 12 as illustrated in Fig. 4. A cooperating movable clamp member 90 is provided to engage the other lateral face of belt 12. Member 90 is carried by a vertical pin 92 and supported for lateral movement in a slot 94 in` the member 68. One end of a lever arm 96 engages the pin 92 to provide the desired clamping and unclamping movement of member 90.

In similar manner, another fixed clamping member 98 is mounted on the outer edge of the other outside belt 36 and is fixed to the follower member 68 by a bolt 100. A cooperating movable clamp member 102 is supported on a vertical pin 104 movable cross-wise of the belts in a slot 106. One end of a lever 108 carries the pin 104 and provides the desired clamping and unclamping movement of member 102. As indicated particularly in Fig. 4, the angular disposition of the lateral edges of the respective belts and associated clamping members not only provides for driving engagement between the belts and the follower members 68, but also assists in preventing any upward removal or undesired rocking action ofthe follower member 68 with respect to the belts 12 and 36.

The operating mechanism for the clamps is best seen in Fig. 2. As shown in this view, the remaining ends of lever arms 96 and 108 are pivoted to each other by a vertical pin 110. The location of this pivot point or pin' rearwardly of the transverse line defined by the pins 92 and 104 of the clamping members provides in effect a toggle linkage. This toggle tightens the clamping engage ment of the parts with the belts when pivot point 110 is moved toward the transfer station and disengages the clamping members when the pivot pin 110 is moved rearwardly.

For convenience in operation of this toggle linkage, an actuating arm 112 is provided. One end 114 of this arm is pivoted at 116 to an outer edge of the follower member 68. The other end of the actuating arm 112 carries a suitable finger piece 118. A spring 120 is connected at one end to the actuating arm 112 and at the other end to a suitable connection 122 on the follower member 68. Pin 110 of the toggle linkage engages a suitable hole or slot (not shown) in the lever arm 112. Under the action of spring 120 the lever arm is urged toward the transfer station and thus the spring tends to maintain the clamping engagement of the parts for movement of the follower member 68 with the belts 12 and 36.

When it is desired to withdraw the follower member, for example in order to replenish the supply of sheets carried by the belts, it is merely necessary to pull rearwardly on the handle piece 118 against the resilience of spring 120. This action will move the pivot pin 110 rearwardly and disengage the clamps from the belts, so that the follower members 68 can slide rearwardly along the path determined by engagement of guide 80 with track 74. The relative location and orientation of the parts provides for convenient operation during reloading. Thus the application of force to lever 112 in a rearward direction not only dis-engages the clamps, but also moves the follower rearwardly as desired.

Auxiliary followerl f mechanismv Theother vof these* units@` `according" to" a special `feature'of the-present invention, is an auxiliaryfollower member designated `generally at`124 (Figure 1)` `isfprovided. One of the `primary1- purposes of this follower member is tofrnaiutain the existing supplyjof sheets at the' desired angle for preserrtation tol the transfer station. Thus the auxiliary follower assists in supporting the upper edges of the sheets and prevents the `transmission of undesii'ed-l excessive forcesf'tofthe lower follower member 68 and its pusherxportionl.. This; follower also urges the sheets towardthe. transfer station when the. follower 68, describedjabove, is retracted for insertion of. an additional supply ofsheets. Y 4

`Follower 124 includes a body "portion126` adapted to engage lanclf be supported by the upper edges of 4one or moreof the rearwardly located sheets inthe supply. The. follower" alsol includes a-depending. arige 128 adapted to engiigebelind the frearmostl sheet.' of the supply. `An upward' extension of `thef'llange`128l provides a suitable ngerlpiece 130 for'manipulation ofthe follower1'24. Ai screwv or otherconnecting'rmemben132' on .the follower i i `frr'avidesmeans forattacliment"of one `end` of Va ll'exible. tensioning, memberjlkl. v v v The follower valso includsa' switchactuating portion 136, inthe form'of'an.` inclined ':'am` ,a`dapted to.l engage and the f operating 138 of a' suitable `,svi/itch '140. Switch 1'40"is connected" by 'wires'139` and to the. powermeans ('notfshov/mf controlling thevacuum pump whichappliesl suction tothe transfer.` mechanism. fIhe switch 140 may also be connected in circuit withlswitch 248 (described below) tofs'top. further. feeding movement off the card'. supplying belts v.12"36 and 38, wheneverfthe supply of boards or` sheetsi's depletedlto, the pointv where the follower portion 136 engages the switch arm `138`.

As indicated belowfsnitablewignal devices are provided. to; warmtheI operator. v when the. .supply is... nearing thisffstage. of.v depletion. Incase thesignalis ignored,

and card afdvancingpmechanism.

orden tounge the. follower. 124'T toward the. transfer station, the, .,exible tensioning `member 1-3l4v .has` its: re.- mote. endaattachedto a. suitableweighb member; 142. Between., the.` follower: 124 and weight. member.- 142. a suitable. systemT of. pulleys is provided-toi guide the. flexible tensioning;,member 134. througli-A av desired' path. Thus; theendof thertensi'oning membenltlfnearest theufollower 1-24fiirst;passesaroundthepulley 144 (E igzfZ) supportedk on., thefadjustable. upper guide. support 146 by` a vertical.` shaft or pivot 148. The pivot is in the form of ascrew member whichisslaterally adjustable along the'support 14f6iby.'1neans:o a lateralislots150..

Thefpvot. screw also. holdsy the upper guide-14zxon-` snppcuzt.A 146; Forv this purpose.: the.-V guide basi-portions 152. which lit. 4thea `support for, sliding z movement. along the. supporti whenrthefscrew:,148;is loosened. Switch 140 is also. supportedr on; guide 14.by` an armi154.- Thus the lateral. position! of the .follower member"124,'j uppersguide. 14 and switch 140 can be shifted with respect to support` 14,6.- `to. accommodatedilerent. widths of* sheets;

.From thegpulley 144 the line-134 passes laterally to a pain ofnpulleys 156. andi'158.. *As viewed infl-T-ig; 2,;the.v linez-1341passesvbeneathfpulley'156 Which`-is rotatabl'eio'n: aiihorizoutal axis.: parallel ton the directio`n:.offmoverneutV of the feed; belts. -Aften passing: beneath pulley 156i the'. line extends upwardlyf oven andi-around:pulley"158 which' is, rotatable: on; afhorizontalfaxis` oriented'. laterally 'across' the direction of movement-fofcthfeedbelts; :Pulleyf158f is in alignment with the rotatabledrum 160,v the effective pitch of which is thesanieas the yeective pitch of the beltsfzon theed'nivingfspulleys- 402 f 42v and144. The'line 13:4? passes larounditlieV4 peripheryi of' thisi drum 160AY one or merel times "to "insure *'ti'glitfrictional:` 'driving engagement betweemtlie'dum* ltllndtheline. "Theline' then passesV switch` 140.l will` stop nthe `operation( ofY the suctionfpurnp;

"6 over a suitable additionalpulley 161 (Figure- 1).` and thus tothe weight member'142.

Therdouble pulley arrangement shown at 156 and,15 8 in Fig. 2 is designed to insure alignmentof thel line 13.4 with the drum 160 for all positions of vertical' adjustment of the upperguide support 146.

The laterally projecting upper guide. support'146iu turn includes a= slide or vguide portion. 162 mounted. for upward and downwardl adjustment along theginclined vertical support member 164. Member 164 in effectprovides a trackway for the portion 162` and this upwardly. extending trackway is connected to the frame of the apparatus at` its base 166 by suitable bolts` 168. Clampingbolts 170 and 172 threaded into the'upper guidevsupport portion 162 provide. for clamping engagement f the edge portions 174 and 176 with the cut-away track portions 178 and `180 v(Fig. 3).4 Theisupport `164 ,extends at the same desiredI angle as thev angle at which the sheets are to be held in the transfer station.

By means of this 'arrangement Vtl'le vertical location of the upper guide supports can be variedto change: its spacing above the belts 12, 36 and 38 in order to accommodate sheets of different vertical height. The angle of support 164 keeps the guide in vthe proper relative lonigtudinal location with respect' to the transfer station in all positionsof adjustment. Nomatterwhat position of adjustment is chosen forthis purpose, however,.double pulley arrangement 156.andv 158 provides a convenient means of feeding the flexible tensioning member 134 directly tothe periphery of drum 160, even through the angle. atwhich the' line 134vapproaches. drum 160 varies according'to the. adjusted height atwhich the 'guide' support is located. If a single pulley were used in place ofthe double pulleys 156 and 158,. this change in angle of. approach could result in disengagement of the line from. the single pulley in certain positions of adjustment.

Follower drum driving mechanism The drum 160 whichfcontrols movement of the line 134' and thus controls. movement of. the upper follower 124 under the iniluence of its weightA member 142,.` includes a lateral driving face 184 (Fig. 5). Frictionclutch. members .186- are adapted `to engage this face 184 to rotate the member 160. The drum 160 is. supported by a hub orbearing portion 182. for free rotation onithe shaft 46 which drives theA belt members.

The clutch surfaces 186 are vcarried by a clutch member 188 which is also mounted on shaft 46. A cross pin. 190i passes laterally throughthe.clutchfmember 188- and alsothrough the'slot 192 'in shaft 46. The vpin and slot arrangement provides for positive rotation of the clutch member 188 with` shaft 46, but permits limited axial movement of clutch member 188 along the shaft.

One end of a spring member 194 engages the clutch member 188' -on the side'opposite. the drum 160. The other end of the spring 194 engages. the opposed surfacey of pulley member 40 which is fixed to the shaft 46. Spring 194 is 'under compression and thus normally urges the clutch member 18S-toward the drum 160 so that the surfaces 186 are vin frictional driving engagementwith the surface 184 of the drum. With the parts in this position,.

the drum 160 will be rotatedat the same angular speed as the pulleys 40, 42 land 44. Thus the cord or line 1'34, which is wound around the drum 160, willbe-permitted to move at the same linear speed as the belts 12, 36 and 38. This movement will urge the upper follower member 124 toward the transfer station whenever the belts are moved and in exact synchronism. with the movement ofl the` belts..

To provide for manual disengagement of the clutch,.

ries a -manuallyoperable. knob or handle portion 200. Pressure against the end of this knob 200 in a direction extending axially along the shaft toward its opposite end, will force pin 190 and associated clutch member 188 t0 theleft in Fig. and out of engagement with drum 160.

Thus when the knob 200 is pushed inwardly, the drum 160will be free to rotate. The follower member 124 can then be-drawnlrearwardly away from the transfer station against lthe urging of the weight member 142. Once the-follower 124 has been engaged behind an additional supply of cards (which may be inserted as shown in Fig ure l), the weight 142 will draw the follower into firm engagement with the cards so that all the cards are in abutting face-to-face engagement for subsequent feeding andy supply movements. The clutch button 200 may then be released -so that the clutch will again engage drum 160 and insure furthermovement of the line 134 and follower 124 in exact synchronism with the belt member.

- As indicated above, another feature of the present inventionris the provision of improved means adapted to drive the belt members to-feed a new sheet to the transfer station whenever the previous sheet has been removed. In this case, the desired driving movement for shaft 46 is advantageously obtained from the conveyor shaft 32 of the main conveyor 30. Details of the driving mechanism are shown particularly in Figs. l, 5 and 6. In the latter figures, a gear or ratchet member 202 is keyed at 204 to the belt drive shaft 46. Ratchet member 202 is provided with `a series of ratchet teeth 20S around its circumference. Rotationof the ratchet gear will accordingly drive shaft 46 through identical angular movements. v-For transmission of the desired actuating forces to the ratchet member 202, a clutch member 208 is `also mounted on shaft 46. Clutch member 208 includes a hub portion 210 which is mounted for free rotation on shaft 46 as shown. The bearing portion 210 permits back and forth movement of the clutch member 208 in first one direction and then the other, i. e., in the desired angular direction of movement of shaft 46 and then in the opposite direction.

The desired reciprocating movement of clutch member 208 is obtained by means of a cam follower 214 lattached to the lower end 212 of the clutch member by a suitable bolt or shaft 216. As shown particularly in Figure l, the cam follower 214 is adapted to engage the surface of an appropriate cam 218 keyed at 224 to the main conveyor shaft 32. Cam 218 includes a plurality of raised portions 220 and intervening dwells or retracted portions 222. Spring 226, connected at 228 to the clutch member 208, pulls the cam follower 214 against the periphery of cam 218.

Rotation of shaft 32 thus causes the lower end 212 of the clutch member 208 to shift between the heavy and dotted line positions of Fig. l as the successive cam portions engage the follower 214. The number of cam projections and the extent of movement required by the cam for clutch member 208 are coordinated with the number and spacing of the ratchet teeth 205 to rotate shaft 46 far enough to replace the cards at the transfer station as needed.

To transmit the desired movements from the clutch member 208 to the ratchet member 202, a suitable pawl 230 is provided. The pawl is pivoted at 232 on clutch member 208. lt includes a point or tooth 234 at one end, which is designed for engagement with the ratchet teeth 205. Thus movement of the clutch mem-ber 208 from right to left in Fig. 6 will rotate the ratchet member 202 whenever the pawl point 234 is in engagement with one of the teeth 205. The inclination of the teeth permits movement of the clutch member in the opposite direction without reverse rotation of ratchet member 202.

A spring 236 is connected to the pawl member 230 in such a manner as to urge the pawl point 234 normally 8 out of engagement withthe ratchet teeth 205. The pawl member 230, however, includes an oppositely projecting lever arm portion 238 which is connected by a further spring 240 to the core member 244 of a suitable solenoid 246. When the solenoid is energized, thecore member 244 is pulled downwardly in Fig. 6 and spring 240 is tensioned to rock the pawl V230 into engagement with ratchet teeth 205 against the urging of spring 236. .When the solenoid 246V isdeenergized, the spring 236 restores the pawl member 230to its retracted ordis-engaged position.

Automatic control of belt feed As indicated above, the desired feeding Ymovement for shaft 46 is obtained in response to the absence of a sheet from the transfer station 18., For this purpose, a feeler or sensing arm 250 is located at one side of the supply of sheets so that the arm will be engaged and shifted by the leading sheet as the sheet actually enters the transfervstation. Feeler arm 250 is carried by a suitable switch unit 248. The switch is connected in circuit with solenoid 246 and a suitable current source (not shown) by connecting wires 252, 254 and 256. When a sheet is in position at the transfer station, the switch is held in position to de-energize the solenoid. Thusthe movement of clutch member 208 is not transmittedjto shaft 46. But after one or more of the leading sheets is removed, the feeler arm movesand the solenoid is energized until the resulting movement of shaft 46 by the clutch members has brought another sheet into position. In one practical embodiment of the machine, the flexibility of the suction cups makes it possible to draw several cards successively from the transfer station, before it is necessary for the sensing arm 250 and switch 248 to call for more cards. Then the feeder may operate to advance several cards into the transfer station before itis de-energized.

Signal device To warn the operator when the supply of sheets on the belt members is approaching the point where replenishment of the supply is needed, a suitable signal device is provided. This signal device includes a feeler arm 258 adapted to engage the sides of the sheets somewhat behind the point at which the upper follower member would otherwise engage the switch arm 138 to de-energize the vacuum pump and sheet feeding mechanism. VThis feeler arm 258 is connected to asuitable switch 260. The latter is connected in turn to a signal light or other signal device 262, by appropriate Wiring 264, 266 and 268. The switch and signal light are connected by these wires to a suitable current source (not shown) in know manner. Y

As long as the supply of sheets extends back far enough to engage the feeler arm 258, the signal light 262 will be de-energized.V If the vrearmost sheet passes toward the transfer station from the feelery arm 258 so that no sheet is in engagement with the arm, the position of the arm will be permitted to change and the switch 260 will cause the signal light to be energized. Thus the operator will receive timely warning that additional sheets must be supplied.

The desired further sheets may be inserted as shown in dotted outline in Figure 1. For this purpose, the lower follower arm 68 is first retracted to the dotted line position of Figure 1. After added sheets are inserted, they are pushed firmly toward the transfer station and against the rearmost sheet of the previous supply. The upper follower arm is then lifted, clutch knob 200 pushed inwardly, and the follower reinserted above and behind the rear sheet of the new supply.

Accommodation of derent sheet sizes One of the possible uses of the present sheet feeding apparatus is the feeding of circuit boards or other electrical component boardsto the conveyor member 30 for further processing. In many applications, thesize of the board will vary. In order that the present apparatus may have. maximum futility in connection with boards of different3sizes,;provision hasbeen. made for universaladjllSlQmGntl. to: accommodate4 variations# in` Aboth dimensions of` the.bo ards.A

As previously described in connection. with.Fignre 1, the .boards are engaged by ein-upper. g-uidememberi 14 1ocated justahead of. the transfer station at which the leadingboard 18 is'. to be located. The upper guide member '174; is normally positioned; a predetermined 2 dis4 tancepabove. thebelt members which is less than the vertical lengthof the individual boards or sheets themselves. Thus Athe guide. member 1 4 engages the upper edges of the sheets and requires..thern tojbetilted to` the desired predetermined angle as. 'the sheet passes into the transfer station...

.'Ifheve rt ical. ;location of the upper guide: member 14 maybefchanged o r adjustedalongthe liner of desired inclinationofthersheets. byj-,the mechanism already described im connection with ligs. VZand 3. vOnce `this upper vguidelis placed in its,` adjusted. position, 'it will engage, only` 'those. .sh eets located just behind, the. transfer station. '1`hus: the guide. location jrgrovidesy a free. path through. w,hich. the 1eadin g. sheet can V b e. moved. upwardly as. as longitudinally away; from. the' transfer station.

The ppsitioncf. thelower, edgev `of eachz board which reaches. theftransfer; station isgdeiined by the upwardly inclined ramp or stationary guide portions shownfor example at 16 in Figure 1. A plurality of these ramp or guide pont-ions areprovided by means of the. 'arrangement shown inlFig,2.

In this figur`e,a cross bari270 'extends across fthe machine belowthe level of the'r upper surface of' thebelts andi somewhat ahead of the beltdrivingfpulleys'. A hub portion: `2-72 isi mountedonthe rod l270'for axiafadjustment alongtthe rodi This hubrpor'tionjcarries'a fixed guide and support member 273whichfhas an upwardly` inclined'Av ramp portion-274 similartothe portion 1"'6- of Figure: 1. *Aclamping screw 275 maintains this" guide -in its adjusted position on rod 270. This screw can be loosened for adjustment of the guide laterally across the direction of feed to accommodate different sheet widths. A similar adjustable guide member is carried by a hub portion 276 and extends rearwardly at 278, with the inclined ramp portion 16 previously noted. For one ex- .treme edge of the boards, a fixed guide 280 is provided with a ramp portion 281.

The parts are shown in Fig. 2 adjusted for the maximum width of sheet for which the apparatus is designed. If narrower sheets are to be processed, the support member 273 and its ramp portion 274 will be shifted toward the belt 36 far enough to accommodate one edge of the desired smaller size sheets when the other edge of such sheets is carried by the fixed guide 280 and ramp 281. The belt member 38 can then be adjusted away from belt v36 to provide a moving support for the edge of the smaller size sheet. Fixed belt 12 will still be operative as a means of driving the follower member 68, even though it will not engage the bottom of a narrower board. The desired adjustment of the central belt member 38 is readily achieved by adjustment of the clamping screw 281 (Fig. by which the pulley 44 is secured to shaft 46. A similar adjustment is provided for the rear pulley 52.

The invention also provides means for adjustment of the guide member 66 to accommodate narrower sheets than those for which the device is set in Fig. 2. For this purpose, the guide 146 has vertically depending end portions. The forward end is carried in a hub 282 and is secured in a desired vertically adjusted position by a set screw 284. The hub portion 282 is connected in turn to a laterally adjustable hub 286 mounted for axial movement along the rod 270. The clamping screw 288 holds this end of the assembly in its adjusted position.

Similarly, the rearwardly located depending end of guide member 66 is received in a hub portion 290 on which it is secured for vertical adjustment. Portion 290- in turn is connected-to alaterallymovablehub292 whichcan be'` clampedv in. a desiredv adjusted lateral position on laterally extending guide-rod 29.4. Thus the-guide member 66'for one edge of the-sheets is universally adjustable bothl vertically toacc'ommodatesheets of different vertical dimensions and laterally.l to accommodate sheets` of different width;

driving-engagement ofthe follower members 68 with the' outside belt fori all board1 sizes.

In conclusion,.itshouldtbe noted that the sheet feedingV4 apparatus describedV in'detailin the foregoing application substantially accomplishes the objectives set forth at thebeginning of this speciiication'and-` provides a convenient, economical andi.eicientfdeviceffor the supply of a plurality of sheetstsuccessively toa transfer station. While this apparatus has 'been particularly designed. for theV relatively `rigidi circuitfboards; utilized in'` the automatic assembly of;electricalcomponents, many features of the invention described. herein willlbe applicable to other uses. Since minor variationsiand changes in the exact details of theapparatus; features will be apparent to persons'skilled in this eld, -it7 isf intended that'this invention sha-ll cover all such changesandy modifications as fall withinttbe; spirituandscope.- of'` theattached claims.

Now therefore we claimz. i Y

`1'.`\She`et`i supply means.- comprising aty least one belt member having a portion adapted to engage one edge of each of a plurality of sheets and move said sheets forwardly toward a transfer station at one end of said portion, rotary shaft means for driving the belt member portion toward said station, a follower member having a portion engaging the rear surface of at least one rearwardly located sheet, a rotary member, means for mov ing said follower member toward said station in response to rotation of said rotary member, and connecting means between said rotary shaft means and said rotary member for driving the latter and moving said follower member at the same rate and direction as said belt portion, said connecting means including manually operable clutch means for selectively disconnecting the rotary member and shaft means for independent withdrawal of the follower member during insertion of additional sheets.

2. Sheet supply means according to claim 1, having a second follower member adapted to engage the rear surface of at least one rearwardly located sheet, means for releasably clamping said second follower member to said belt member portion for movement thereby, and manually operable releasing means for said clamping means.

3. Sheet supply means comprising at least one belt member having a portion adapted to engage the edges of a plurality of sheets and move said sheets on edge toward a transfer station at one end of said portion, a follower member engaging arearwardly located sheet, a flexible tensioning member connected to said follower member, a weight member to which said tensioning member is connected, said weight member urging the tensioning member in a direction to pull said follower and said sheets toward the transfer station, and a rotary member driven at substantially the same peripheral speed as said belt member and in synchronism therewith, a portion of said flexible tensioning member between said weight and said follower being positioned in driving engagement. with said rotary member and thereby synchronizing the 1-1 movement of the follower, under the urging of said weight, with the movement of said belt.

4. Sheet supply means according to claim 3 having manually operable clutch means between said rotary member and said belt member thereby providing free movement of the rotary member and tensioning member when the clutch is disengaged for resetting movement of the follower member behind an added plurality of sheets.

5. Sheet supply means comprising at least one belt member having a horizontal portion adapted to engage the lower edges of a plurality of sheets and move said sheets on edge toward a transfer station at one end of said portion, means for driving said belt to move said portion toward the station, a guide member engaging the upper edges of the leading sheets just before they reach said station, the guide member being spaced perpendicularly above the belt a distance less than the vertical dimension of the sheet and thereby insuring tilting of each sheet at a predetermined angle to the belt with its upper edge slightly behind the lower edge as the sheet reaches the transfer station, and at least one follower member engaging a rearwardly located sheet and holding said sheet at an angle substantially similar to said predetermined angle.

6. Sheet supply means according to claim 5 in which said guide means is located behind said transfer station, the leading sheet, when located exactly at said transfer station, being supported at said predetermined angle by engagement with the rearwardly located sheets, the relative location of the guide member providing a clear path for forward and upward movement of the leading sheet out of said transfer station.

7. Sheet supply means according to claim 5 in which said one follower member engages the upper portion of a rearwardly located sheet and is supported thereby, and a flexible tensioning member connected to said follower and urging it toward said station.

8. Sheet supply means according to claim 7 in which the driving means for said belt includes a disengageable clutch and a rotary drum driven through'said clutch, said flexible tensioning member engaging' said drum' and being driven thereby to urge the follower member toward' the transfer station.

9. Sheet supply mechanism comprising at least one belt member having a portion adapted to engage the edges of a plurality of sheets and move said sheets toward a transfer station at one end of said portion, first and second follower members each adapted for engagement with a rearwardly located sheet to urge said sheets toward said station, means releasably connecting said first follower member to said belt portion to move the rearwardly located sheets with the belt, manually operable releasing means for said connecting means providing for disengagement of the connecting means and relative rearward movement of said lrst follower member along said belt for insertion of additional sheets, and maintaining means for maintaining the second follower member in engagement with the existing supply of sheets and urging said sheets toward the transfer station during disengagement of said first follower member and insertion of said additional sheets, said maintaining means including a iiexible tensioning member and the second follower member is supported solely by engagement with said sheets under the urging of said flexible tensioning member.

References Cited in the tile of this patent UNITED STATES PATENTS Re. 21,489 Kleineberg et al June 25, 1940 620,841 Dexter Mar. 7, 1899 1,069,848 Brown Aug. 12, 1913 1,154,237 Dixon Sept. 21, 1915 1,693,986 Kluge et al. Dec. 4, 1928 1,982,923 Meredith Dec. 4, 1934 2,361,907 Baker et al. Nov. 7, 1944 

